There are a number of equilibrators known for preparing a calibration standard and one or more test samples for a blood gas analyzer. In one such apparatus, the sample or standard is prepared by blowing gas onto the surface of a solution held in a tube or other type of cell, while the solution is being oscillated or spun to increase the gas-liquid contact area. Such an apparatus is relatively complicated and expensive, requiring means for accomplishing the spinning, among other things. Also, a relatively long time is required to accomplish equilibration, since even with spinning, the available surface area for absorption of the gas is relatively small. Thus, each standard or test sample generally requires from 20-30 minutes to equilibrate. Further, it is customary to prepare one standard and two test samples in each 8 hour shift, thus leading to a down time of 1 to 11/2 hours per shift for preparing samples for the calibration of a blood gas analyzer and for the testing thereof.
Another prior art gas-liquid equilibrator will produce samples in a much shorter period of time by bubbling gas into a cell below the surface of the liquid being equilibrated therewith. The cell itself is generally of a polymeric material and is matingly held within a cavity in a block of copper or other heat conductive metal. Equilibration time is fast and more than one standard or test sample can be produced simultaneously through providing a plurality of bores in the copper block and a plurality of gas lines for delivering gas, one for delivering gas beneath the surface of each of the solutions in each of the cells. While an apparatus as just described has significant advantages over other prior art apparatus, the solutions prepared in the cells of such an apparatus must be capped and transferred elsewhere by pouring or by being sucked up into a syringe or the like. While this can be readily carried out by a trained technician, it does introduce a possibility for operator error.